Given a DNA strand, return its RNA complement (per RNA transcription).
Both DNA and RNA strands are a sequence of nucleotides.
The four nucleotides found in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T).
The four nucleotides found in RNA are adenine (A), cytosine (C), guanine (G) and uracil (U).
Given a DNA strand, its transcribed RNA strand is formed by replacing each nucleotide with its complement:
G
-> C
C
-> G
T
-> A
A
-> U
For installation and learning resources, refer to the exercism help page.
For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:
gem install minitest
If you would like color output, you can require 'minitest/pride'
in
the test file, or note the alternative instruction, below, for running
the test file.
Run the tests from the exercise directory using the following command:
ruby rna_transcription_test.rb
To include color from the command line:
ruby -r minitest/pride rna_transcription_test.rb
Rosalind http://rosalind.info/problems/rna
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
require 'minitest/autorun'
require_relative 'rna_transcription'
# Common test data version: 1.0.1 cb1fd3a
class RnaTranscriptionTest < Minitest::Test
def test_rna_complement_of_cytosine_is_guanine
# skip
assert_equal 'G', Complement.of_dna('C')
end
def test_rna_complement_of_guanine_is_cytosine
skip
assert_equal 'C', Complement.of_dna('G')
end
def test_rna_complement_of_thymine_is_adenine
skip
assert_equal 'A', Complement.of_dna('T')
end
def test_rna_complement_of_adenine_is_uracil
skip
assert_equal 'U', Complement.of_dna('A')
end
def test_rna_complement
skip
assert_equal 'UGCACCAGAAUU', Complement.of_dna('ACGTGGTCTTAA')
end
def test_correctly_handles_invalid_input_rna_instead_of_dna
skip
assert_equal '', Complement.of_dna('U')
end
def test_correctly_handles_completely_invalid_dna_input
skip
assert_equal '', Complement.of_dna('XXX')
end
def test_correctly_handles_partially_invalid_dna_input
skip
assert_equal '', Complement.of_dna('ACGTXXXCTTAA')
end
# Problems in exercism evolve over time, as we find better ways to ask
# questions.
# The version number refers to the version of the problem you solved,
# not your solution.
#
# Define a constant named VERSION inside of the top level BookKeeping
# module, which may be placed near the end of your file.
#
# In your file, it will look like this:
#
# module BookKeeping
# VERSION = 1 # Where the version number matches the one in the test.
# end
#
# If you are curious, read more about constants on RubyDoc:
# http://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/constants.html
def test_bookkeeping
skip
assert_equal 4, BookKeeping::VERSION
end
end
class Complement
DNA_KEYS = 'GCTA'.freeze
RNA_KEYS = 'CGAU'.freeze
def self.of_dna(dna)
return '' unless valid_dna?(dna)
dna.tr(DNA_KEYS, RNA_KEYS)
end
def self.valid_dna?(dna)
(dna.chars - DNA_KEYS.chars).none?
end
end
module BookKeeping
VERSION = 4
end
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.
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